# Tailoring of an Electron-Bunch Current Distribution via Space-to-Time Mapping of a Transversely-Shaped Photoemission-Laser Pulse

## TL;DR

This paper demonstrates a novel method to convert a transversely-shaped laser pulse into a temporally modulated electron bunch, enabling new possibilities for ultrafast electron applications and compact light sources.

## Contribution

It introduces a space-to-time mapping technique for tailoring electron bunch current distributions from transversely-patterned laser pulses.

## Key findings

- Validated the method with numerical simulations.
- Showcased tunability of current-distribution parameters.
- Proved the concept's applicability to various temporal shapes.

## Abstract

Temporally-shaped electron bunches at ultrafast time scales are foreseen to support an array of applications including the development of small-footprint accelerator-based coherent light sources or as probes for, e.g., ultrafast electron-diffraction. We demonstrate a method where a transversely-segmented electron bunch produced via photoemission from a transversely-patterned laser distribution is transformed into an electron bunch with modulated temporal distribution. In essence, the presented transformation enables the mapping of the transverse laser distribution on a photocathode surface to the temporal coordinate and provides a proof-of-principle experiment of the method proposed in W. S. Graves, et al. as a path toward the realization of compact coherent X-ray sources, albeit at a larger timescale. The presented experiment is validated against numerical simulations and the versatility of the concept, e.g. to tune the current-distribution parameters, is showcased. Although our work focuses on the generation of electron bunches arranged as a temporal comb it is applicable to other temporal shapes.